// (c) Copyright Ascensio System SIA 2009-2024
//
// This program is a free software product.
// You can redistribute it and/or modify it under the terms
// of the GNU Affero General Public License (AGPL) version 3 as published by the Free Software
// Foundation. In accordance with Section 7(a) of the GNU AGPL its Section 15 shall be amended
// to the effect that Ascensio System SIA expressly excludes the warranty of non-infringement of
// any third-party rights.
//
// This program is distributed WITHOUT ANY WARRANTY, without even the implied warranty
// of MERCHANTABILITY or FITNESS FOR A PARTICULAR  PURPOSE. For details, see
// the GNU AGPL at: http://www.gnu.org/licenses/agpl-3.0.html
//
// You can contact Ascensio System SIA at Lubanas st. 125a-25, Riga, Latvia, EU, LV-1021.
//
// The  interactive user interfaces in modified source and object code versions of the Program must
// display Appropriate Legal Notices, as required under Section 5 of the GNU AGPL version 3.
//
// Pursuant to Section 7(b) of the License you must retain the original Product logo when
// distributing the program. Pursuant to Section 7(e) we decline to grant you any rights under
// trademark law for use of our trademarks.
//
// All the Product's GUI elements, including illustrations and icon sets, as well as technical writing
// content are licensed under the terms of the Creative Commons Attribution-ShareAlike 4.0
// International. See the License terms at http://creativecommons.org/licenses/by-sa/4.0/legalcode

import { useEffect, useState } from "react";
import { getSystemTheme } from "../utils";
import { setCookie } from "../utils/cookie";
import { ThemeKeys } from "../enums";
import { SYSTEM_THEME_KEY } from "../constants";

export const useThemeDetector = () => {
  const isDesktopClient = window.AscDesktopEditor !== undefined;
  const [systemTheme, setSystemTheme] = useState(getSystemTheme());

  const systemThemeListener = (e: MediaQueryListEvent) => {
    setSystemTheme(e.matches ? ThemeKeys.DarkStr : ThemeKeys.BaseStr);
    if (e.matches) {
      setCookie(SYSTEM_THEME_KEY, ThemeKeys.DarkStr);
    } else {
      setCookie(SYSTEM_THEME_KEY, ThemeKeys.BaseStr);
    }
  };

  useEffect(() => {
    if (isDesktopClient) return;

    const mediaQuery = window.matchMedia("(prefers-color-scheme: dark)");
    mediaQuery.addEventListener("change", systemThemeListener);

    return () => {
      if (isDesktopClient) return;

      mediaQuery.removeEventListener("change", systemThemeListener);
    };
  }, [isDesktopClient]);

  return systemTheme;
};
